crusty eyes

My son is sick with a cold and been getting gross eye junk that crusts his eyes in the morning. His eyes aren't red and he's not scratching them so it doesn't look like pink eye (but I'm not an expert). Is this something that just comes with colds sometimes or should I be worried? I'm on the fence about bringing him to the doc.

DD had a head cold a month or so ago and it started with two days of gunky eyes when she woke up. The gunk was white, not green and there wasn't a whole lot of it, just enough to crust her lashes, not enough to stick them shut. After a couple days it was just the usual runny nose and cough.

I took DS to the doc yesterday and he had a mild lung infection :/ he has been acting completly fine but still coughing a bit, a stuffy nose, and occasional eye gunk. Although the eye gunk and snot are green...I guess bc of the infection. He is on antibiotics now.